Protective garment

ABSTRACT

Protective clothing comprises at least one protective material including an array of one or more superposed layers of woven fabric, wherein each fabric layer is flexible and includes at least one fabric, made of yarns having a strength of at least 900 MPa, that is joined to at least one polymer film, and wherein the protective material has an outer surface facing the side of attack and an inner surface facing away from the side of attack, wherein the protective material also has at least one layer of felt, placed in every case on one of the fabric layers.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of InternationalApplication No. PCT/EP02/11735 filed on Oct. 19, 2002, the disclosure ofwhich is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to protective clothing comprising at least oneprotective material.

2. Description of Related Art

Clothing that protects against attack with ballistic or stab weapons isknown. WO 00/08411 describes a stab-resistant material comprising atleast two woven fabrics joined via a polymer film, wherein the fabricsconsist of yarns having a strength of at least 900 MPa and the polymerfilm joining the fabrics has a strength of at least 10 MPa and aflexural modulus of 1500 to 4500 MPa.

While the material disclosed in WO 00/08411 offers good stab resistance,a need exists for protective clothing of a protective material thatensures even better protection for the same areal weight. Protectiveclothing of this type would have the additional advantage that aparticular measure of protection would be attainable with a lower arealweight than has previously been possible, leading to a higher degree ofcomfort for the wearer.

SUMMARY OF THE INVENTION

The object of the present invention, therefore, is to provide protectiveclothing of a protective material that ensures improved protection forthe same areal weight, or the same degree of protection for a lowerareal weight.

This object is achieved by protective clothing comprising at least oneprotective material comprising an array of one or more superposed fabriclayers, wherein each fabric layer is flexible, and consists of at leastone fabric, made of yarns having a strength of at least 900 MPa, that isjoined to at least one polymer film, and wherein the protective materialhas an outer surface facing the side of attack and an inner surfacefacing away from the side of attack and is characterized in that it alsohas at least one layer of felt, placed in every case on one of thefabric layers.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It has surprisingly been found that owing to the protective materialcontaining in addition at least one further layer of felt, which ispositioned in every case on one of the fabric layers, protectiveclothing is achieved that, for the same areal weight, provides improvedprotection and therefore makes it possible to ensure the same degree ofprotection for a lower areal weight, i.e., for greater wear comfort.

The description that the protective material of the protective clothingof the invention further has at least one additional felt layer that isalways positioned on one of the fabric layers means that the at leastone layer of felt is sewed or stuck to the fabric layer only at discretepoints, or is simply superposed on it. This superposed embodiment ispreferred on account of simplicity of implementation.

Protective clothing that offers especially effective protection, and istherefore preferred according to the invention, is one in which at leastone layer of felt is positioned at the outer surface and/or the innersurface of the protective material.

Another embodiment of the protective clothing of the invention thatoffers especially effective protection, and is therefore preferred, isone comprising at least three fabric layers and having at least one feltlayer positioned between the fabric layers, and in which the number offabric layers facing the outer surface is lower than the number offabric layers facing the inner surface.

It is advantageous if, in the protective clothing of the invention, theat least one felt layer consists of an aromatic polyamide, i.e., of anaramid, and in particular of a p-aramid.

The felt layer can be produced by any of the known manufacturing methodsfor felts, resulting in a layer of felt that is bonded, for example,thermally, by the action of a stream of water or air, or by needling.The felt layer is preferably a needled felt. A felt of this type can beobtained from, for example, Job (Kinna, Sweden).

Furthermore, it is preferred for the protective clothing of theinvention that each fabric of each fabric layer consist of yarns ofstrength between 900 and 8000 MPa, more preferably between 1500 and 6000MPa and most preferably between 3000 and 6000 MPa. Practically allyarns, including those suitable for use in ballistic protection, such asyarns made from polyolefins, particularly polyethylene, or yarns ofpolyamide, polyimide, polyester or poly(p-phenylene-2,6-benzobisoxazole)have strengths in this range. Yarns from aramids, especially those fromp-aramids, have proved particularly favorable.

It has proved most favorable in the protective clothing of the inventionfor the weave of each fabric of each fabric layer to be a plain weave.

It has further proved most favorable in the protective clothing of theinvention for each fabric of each fabric layer to have a fabric density,as calculated by the Walz formula, of between 15% and 80%, andpreferably between 15% and 60%.

The Walz fabric density is calculated from the formulaDG=(d _(k) +d _(s))² ·f _(k) ·f _(s)where

-   d_(k)=substance diameter of the warp yarn in mm-   d_(s)=substance diameter of the weft yarn in mm-   f_(k)=warp threads per cm-   f_(s)=weft threads per cm.

The substance diameter d_(k) or d_(s) of the yarns is calculated asfollows:d=(titre)^(1/2)/[88.5(density)^(1/2)]where d is either d_(k) or d_(s), the titre of the corresponding yarn isin dtex, and the density of the yarn is in g/cm³.

The values given above apply particularly for fabrics with a plainweave. For weaves other than a plain weave, a weave correction factormust be included in the calculation. The following are examples of thevalues used for the weave correction factor for fabrics with specificweaves:

Weave type Weave correction factor 2/2 hopsack weaves 0.56 2/1 twillweaves 0.70 2/2 twill weaves 0.56 3/1 twill weaves 0.56 4/4 twill weaves0.38 1/4 satin 0.49

The fabric density DG as calculated by the Walz formula is multiplied bythese correction factors.

The fabric density DG according to Walz is expressed as a percentage. Incase of highly dense fabrics the values may lie above 100%.

The fact that in the protective clothing of the invention each fabriclayer consists of at least one fabric joined to at least one polymerfilm means, for example, that one fabric is joined to one polymer film.Either the fabric or the polymer film can lie closer to the outersurface of the protective material that faces the side of attack.

In a preferred embodiment of the protective clothing of the invention,each fabric layer consists of a fabric joined on both sides to a polymerfilm.

In another preferred embodiment of the protective clothing of theinvention, each fabric layer consists of two fabrics, joined via apolymer film, whereby it has proved particularly advantageous for eachfabric layer to consist of two fabrics laminated to each other by apolymer film.

It is advantageous if the polymer film joining the two fabrics of thelayer has an elongation at break of at least 80%, for example, 100% or120%.

In the present invention, in a same manner as described in WO 00/08411,the flexural modulus should be determined in accordance with ASTM D-790,the strength of the film in accordance with ASTM D-638, the elongationat break in accordance with ASTM D-638 and the strength of the yarn inaccordance with ASTM D-885.

The polymer film contained in the protective clothing of the inventionhas a strength preferably of at least 10 MPa and a flexural modulus of1500–4500 MPa. A flexural modulus of 2000–3000 MPa is especiallyfavorable. Suitable polymers are hard PVCs having a flexural modulusbetween 3500 and 4000 MPa, or polyurethanes having a flexural modulusbetween 4000 and 4500 MPa.

Polymer films made from a polycarbonate are particularly suitable forbinding the fabrics into a fabric layer. A polycarbonate of this type issold, for example, under the name POKALON N 38 by Color Print(Frankenthal, Germany). A further example of a suitable polycarbonate issold under the name LEXAN 103 by GE Plastics. LEXAN 103 has a flexuralmodulus of 2500 MPa, a strength of 70 MPa and an elongation at break of120%.

It has been found that particularly good protection is afforded by theprotective clothing of the invention that comprises a protectivematerial consisting of an array of several superposed fabric layers,wherein a layer of felt is placed on both the outer surface and theinner surface. This embodiment is therefore preferred, particularly whenthe protective material comprises an array of 6 to 30 superposed fabriclayers, whereby it is most especially preferred, from the viewpoints ofprotective efficiency and wear comfort, that the protective materialcomprises an array of 6 to 25 superposed fabric layers.

A further preferred embodiment of the present invention consists inprotective clothing comprising at least two of the protective materialsdescribed above.

In the protective clothing of the invention, a protective material, orseveral or all of the protective materials, are preferably placed in asheath of textile material, because this allows for easier handling.

The invention will now be described in more detail with the help of thefollowing examples. The protective efficiency will be illustrated bymeans of the stab resistance shown by the protective materials of theprotective clothing of the invention. The stab resistance was tested inaccordance with NIJ (National Institute of Justice) standard 0115.00,protection level KR 2, wherein a spike is dropped on to thestab-resistant material by means of a drop tester. The stab-resistantmaterial is affixed by means of a tensioning strap to a backgroundmaterial consisting of various foams defined in the aforementionedstandard. The spike falls on to the stab-resistant material, pierces it,and penetrates a certain distance into the background material. Thebackground material penetration is measured in mm, and the arithmeticmean determined for several drops. Unlike in the aforementionedstandard, this mean value is designated as the stab resistance.

EXAMPLES 1 TO 6

Fabrics were produced in a plain weave from aramid yarns with a titre of930 dtex and a breaking strength of 3380 MPa. The fabrics containedapproximately the same number of threads in warp and weft. The Walzfabric density was 18.5%, and the fabric weight was 140 g/m². Apolycarbonate polymer film (POKALON N 38, from Color Print, Frankenthal,Germany) having an areal weight of 75 g/m² was placed between twoprewashed fabrics. Lamination of the two fabrics to the polymer film togive a fabric layer was carried out in a temperature range of 220–230°C. and at a pressure of approximately 100 bar.

In Example 1, 16 of the aforementioned fabric layers were superposed andthen secured with a tensioning strap to the background material, and thestab resistance was measured as described above.

In Example 2, 16 layers of felt were superposed and secured with atensioning strap to the background material, and the stab resistance wasmeasured as described above. Each felt layer consists of a 100% p-aramidfelt whose fibers consist of TWARON® fibers of titre 1.7 dtex and length60 mm. These fibers are available from Teijin Twaron. The felt has anareal weight of 350 g/m², is needled and calendered, and has a thicknessof 2.3 mm. A felt of this type is available from Job (Kinna, Sweden).

In Example 3, 14 of the aforementioned fabric layers are laid on two ofthe layers described immediately above. The protective material of theinvention that is thus formed is secured with a tensioning strap to thebackground material with the felt layers facing the background material,and the stab resistance is measured as described above.

In Example 4, two of the layers of felt described immediately above areplaced on 14 of the aforementioned fabric layers. The protectivematerial of the invention that is thus formed is secured with atensioning strap to the background material with the fabric layersfacing the background material, and the stab resistance is measured asdescribed above.

In Example 5, one of the layers of felt described immediately above isplaced on 15 of the aforementioned fabric layers. The protectivematerial of the invention that is thus formed is secured with atensioning strap to the background material with the fabric layersfacing the background material, and the stab resistance is measured asdescribed above.

In Example 6, 14 of the aforementioned fabric layers are placed on oneof the felt layers described immediately above, and one of the feltlayers described immediately above is placed on the 14 fabric layers.The protective material of the invention that is thus formed is securedwith a tensioning strap to the background material, and the stabresistance is measured as described above. The constitution of thetested materials, their areal weights, their individual penetrationvalues and their arithmetic means that, as stated above, are designatedas the stab resistance, unlike in the aforementioned standard, are givenin the following table. The lower the value in the stab resistancecolumn, the better is the stab resistance.

Individual Areal penetration Stab weight values resistance ExampleConstitution (g/m²) (mm) (mm) 1 16 fabric layers 5680 26, 28, 29 27.7 216 felt layers 5600 approx. 25 approx. 25 3 14 fabric layers 5670 29,26, 17, 32 26.0  2 felt layers 4  2 felt layers 5670 22, 15, 24, 23 21.014 fabric layers 5  1 felt layer 5675 12, 20, 18, 30, 16, 13, 17.8 15fabric layers 16, 17 6  1 felt layer 5670 0, 14, 14, 10, 19, 0, 12.4 14fabric layers 27, 15  1 felt layer

The table shows that substitution of even one fabric layer by a feltlayer significantly improves the stab resistance (as is seen fromcomparison of Examples 1 and 5).

In general, the stab resistance in those protective materials where thefelt layer is placed on the outer surface, facing the falling spike, isbetter than in those protective materials where the felt layer is placedon the inner surface, facing the background material (as is seen fromcomparison of Examples 3 and 4).

The best stab resistance was attained with the protective material ofExample 6. For the two individual tests that gave individual penetrationvalues of 0 mm, the spike was even found to be bent. Applied to areal-life threatening situation, i.e., in an attack with a stab weaponsimilar to the spike, this result means that with the use of 16 fabriclayers of the prior art, the spike would penetrate the body to a depthof approximately 28 mm (see Example 1), while with the protectivematerial of the invention of Example 6 the spike would penetrate thebody to only about 12 mm, i.e. 16 mm less deep. Moreover, the arealweight of the protective material according to the invention is, at 5670g/m², even somewhat lower than that of the aforementioned 16 fabriclayers of the prior art (5680 g/m²). Consequently, a protective materialaccording to the invention can be provided with a stab resistance of 28mm and an areal weight significantly lower than 5680 g/m². Thus, for thesame stab resistance of 16 fabric layers of the prior art, theprotective material of the invention offers significantly better wearcomfort.

EXAMPLE 7

Using the spike specified in the aforementioned NIJ standard, which wasfixed in a handle, a tester, using the maximum force, made three stabsmanually on each of the following:

-   -   a) 15 superposed fabric layers, produced as described in the        first paragraph of Examples 1–6, and    -   b) a protective material of the invention, comprising 9        superposed fabric layers, produced as in the first paragraph of        Examples 1–6, a felt layer produced as in Example 2 being placed        on the outer surface, facing the side of attack.

The test materials in this case were placed on the same backgroundmaterial as specified in the aforementioned NIJ standard, but were notsecured to it.

Whereas in a) the spike clearly penetrated the 15 fabric layers, nopenetration was detected in b) and the spike was even bent.

1. Stab-resistant clothing comprising at least one protective materialcomprising an array of one or more superposed woven fabric layers,wherein each fabric layer is flexible, and includes at least one fabric,made of yams having a strength of at least 900 MPa, that is joined to atleast one polymer film, and wherein the protective material has an outersurface facing the side of attack and an inner surface facing away fromthe side of attack, wherein the protective material also has at leastone layer of felt, placed on one of the fabric layers, and wherein theprotective material includes at least one additional layer of felt,positioned on one of the fabric layers.
 2. Stab-resistant clothingaccording to claim 1, wherein at least one layer of felt is positionedat least at one of the outer surface and the inner surface of theprotective material.
 3. Stab-resistant clothing according to claim 1further comprising at least three fabric layers, wherein at least onelayer of felt is positioned between the fabric layers, the number offabric layers from the at least one felt layer to the outer surfacebeing lower than the number of fabric layers from the at least one feltlayer to the inner surface.
 4. Stab-resistant clothing according toclaim 1, wherein the at least one layer of felt includes an aromaticpolyamide.
 5. Stab-resistant clothing according to claim 1, wherein theat least one layer of felt is a needled felt.
 6. Stab-resistant clothingaccording to claim 1, wherein each fabric of each fabric layer includesyarns of strength between 900 and 8000 MPa.
 7. Stab-resistant clothingaccording to claim 1, wherein the weave of each fabric of each fabriclayer is a plain weave.
 8. Stab-resistant clothing according to claim 1,wherein each fabric of each fabric layer has a fabric density, ascalculated by the Walz formula, of between 15% and 80%. 9.Stab-resistant clothing according to claim 1, wherein each fabric layerincludes a fabric that is joined on both sides to a polymer film. 10.Stab-resistant clothing according to claim 1, wherein each fabric layerincludes two fabrics joined to each other via a polymer film. 11.Stab-resistant clothing according to claim 10, wherein each fabric layerincludes two fabrics laminated to each other by a polymer film. 12.Stab-resistant clothing according to claim 1, wherein the polymer filmhas a strength of at least 10 MPa and a flexural modulus of 1500–4500MPa.
 13. Stab-resistant clothing according to claim 12, wherein thepolymer film has a flexural modulus of 2000–3000 MPa.
 14. Stab-resistantclothing according to claim 1, wherein the polymer film binding thefabrics into a fabric layer includes a polycarbonate.
 15. Stab-resistantclothing according to claim 1, wherein the protective material includesan array of several superposed fabric layers, a layer of felt beingplaced on both the outer surface and the inner surface of the protectivematerial.
 16. Stab-resistant clothing according to claim 15, wherein theprotective material further comprises an array of 6 to 30 superposedfabric layers.
 17. Stab-resistant clothing according to claim 15,wherein the protective material further comprises an array of 6 to 25superposed fabric layers.
 18. Stab-resistant clothing according to claim1 composing at least two protective materials.
 19. Stab-resistantclothing according to claim 1, wherein one or more of the at least oneprotective material is placed in a sheath of textile material.